USER GUIDE
UG499: Si828x-AW-GDB Gate Driver Boards
Skyworks Solutions, Inc. • Phone [949] 231-3000 • [email protected] • www.skyworksinc.com
206359B • Skyworks Proprietary Information • Products and Product Information are Subject to Change without Notice
8
November 10, 2022
6. Temperature Feedback
The XM3 power module uses a thermistor to provide temperature feedback to the controller. The resistance of the thermis-
tor sensor is converted to a 50% duty cycle square wave with a frequency that varies inversely with the resistance. The resis-
tance to frequency relationship is displayed in the Table 4 below. The resistance to frequency circuits is located on the high
voltage side to provide direct connection to the XM3 thermistor sensor. Then, a digital isolator is used to transmit the fre-
quency-encoded signal back to the primary side and its differential signals are connected to pin 9 and pin 10 of the JT3 low
side connector.
Figure 4. Thermistor Resistance vs Output Frequency
Table 4: Thermistor Resistance vs Output Frequency
Thermistor Resistance (
Ω
)
Frequency Output (kHz)
13491
4.6
4700
10.3
1928
17.1
898
22.8
464
26.4
260
28.3
156
29.5
99
30.1
